science PAT part 1

high-key mentally unprepared for school

H₂O(ℓ) 

• way of communicating water in liquid form

• First letter (H) is always upper case

(ℓ) 

• Substance in liquid form 

• Not upper case 

• An “L” 

H₂O(ℓ) -> H₂O(s) 

• Physical change  

• Liquid to solid when froze 

• Substance not changed 

Physical change  

• The substance is changed to a different state 

• Substance and formula don’t change 

• Example: Au(s) -> Au(ℓ) 

• No new substance is formed 

Physical property 

• Boiling point 

• Physical change 

Chemical change 

• Substance and formula change 

• State is changed 

• New substance is formed 

Chemical property

• Electrolysis 

• Chemical change 

Matter 

• Particles attracted to each other, creating an object 

• Occupies space and has volume 

• An atom  

• Cannot be chemically created or destroyed 

Mass and atoms 

• Cannot be chemically created or destroyed 

• Conserved in chemical change 

Solution  

• Two components  

• Solute (substance being diluted) 

• Solvent (substance that dilutes the solute) 

Symbolic  

Formulas 

Macroscopic  

• Observations 

• Visible with naked eye 

Microscopic  

• Not visible with naked eye  

• Particle theory  

Pure substance  

• Single kind of matter having predictable properties 

• Compound 

• Element  

Mixture 

• Physical combination of two or more types of substances  

• Homogenous  

• Heterogeneous  

Homogeneous  

Cannot be physically separated 

Heterogeneous  

Can be physically separated  

Mechanical mixture  

• A mixture that is visible with the naked eye 

• Example: chocolate chip cookie (dough and chocolate chips are clearly visible in the mixture), beach sand (can be separated and visible that there are multiple rocks) 

Compound  

Can be broken down into simpler components  

Element  

Cannot be broken down into other components (purest form) 

Formula of compounds 

• The element that is on the farthest left goes first (ex: HCl, hydrogen is further to the left, so it goes first) 

• A mix of two elements, element in compound  

• Covalent rule: add number before element name (ex: dichloride) 

• Ionic rule: no number before (ex: chloride) 

Bohr models 

Show the number of protons and electrons in an element 

Cation and anions  

• Cations are positive 

• Anions are negative  

Electrons/protons/neutrons 

• Electrons: the negative electrical charge. The atomic number  

• Protons: the positive electrical charge. The atomic number 

• Neutrons: subatomic particle that make up every atom. the mass rounded to the nearest whole number subtracted from the protons 

Isotopes  

• Atoms with the same number of protons but different number of neutrons 

• Sometimes makes mass bigger 

• Some have different physical properties 

Covalent  

Two atoms sharing one or more pair of electrons to hold them together 

Valence  

The outer ring, outer orbit 

Groups and periods 

• Groups are up 

• Periods are side

Ionic compounds 

• A metal and a non-metal 

• Have high melting point 

• Net charge must be 0 

• Opposite charges attract 

• conducts electricity

• solid at room temperature

Molecular compounds 

• A non-metal and a non-metal 

• Both in valence shell 

• Covalent bond 

• Non-metals form molecular compounds by sharing valence shells, outer shell 

Gas test 

• If it’s oxygen, it will burn brighter 

• If it’s carbon dioxide, it will go out 

• If it’s hydrogen, it will explode 

Organic compound  

Contains carbon attached to carbon or hydrogen

Inorganic compound 

Carbon that does not connect to hydrogen or carbon 

Macromolecules 

large molecules essential for life made of small organic molecules

Photosynthetic plant 

For every photosynthetic plant, all carbon comes from the atmosphere 

Nutrients 

• Macronutrients 

• Micronutrients 

Macronutrients 

• Fats/lipids 

• Carbohydrates 

• protein 

Micronutrients 

• Vitamins 

• Minerals 

Carbohydrates 

• Simple sugars 

• Function: short term energy source for humans 

• Cellulose is not an energy source for humans, but it is critical to maintain the digestive system 

Proteins 

• Source of C, O, H, N, and S 

• Harder to digest than carbohydrates 

• Source of amino acids

• Function: structure; catalyst (enzyme) 

• Amino acids – nitrogen 

• Example: hemoglobin (Hb) 

Lipids (fats) 

• Source of C, D, H, N, and P 

• Harder to digest than carbohydrates 

• Stored as triglycerides 

• Function: long term energy storage; structure (cell membrane) 

Nucleic Acids 

large biomolecules in all cells and viruses

saturated fats 

healthy fats

Unsaturated fats

less healthy than saturated fats

trans fats

the least healthy fats

Vitamins – micronutrients 

• Organic nutrients needed for essential health 

• Smaller quantities than micro 

• Necessary for proper enzyme function 

Cholesteryl  

• Fat  

• Essential/macronutrient 

• Body manufacturers vitamin d from cholesterol, so you shouldn’t eliminate it 

• Can only produce vitamin d from sunlight 

Fortifying foods 

• Making food stronger 

• In Canada, milk must be fortified with vitamin d 

Minerals 

• Inorganic 

• Natural element or compound 

Diffusion 

high concentration of particles goes to a lower concentration

osmosis

• high concentration to low concentration

• semi-permeable membrane

Active Transport 

cell uses energy to moves things where they are needed

ingestion

consuming something orally (eating/drinking by mouth)

absorption

nutrients or chemicals taken in though skin or stomach

Bioaccumulation

the process where toxins build up in a living thing over time

biomagnification

the process where toxins get bigger as it passes though the food chain (larger organisms have a higher build up of toxicity)

concentration

the amount of something in a certain amount of liquid or gas

PPM, PPB, PPT

• PPM: parts per million

• PPB: parts per billion

• PPT: parts per trillion

toxicity

how harmful a substance is to a living organism

LD50

the amount of substance it needs to kill half a population in a test

Kg to g

multiplied by 1000

g to mg

multiplied by 1000

mg to g

divided by 1000

g to kg

divided by 1000

ml to L

divided by 1000

L to ml

multiply by 1000

Pollution  

Process of introducing harmful substances into the environment

Pollute 

 Substance that has harmful effects to an organism 

Toxin  

Natural substance that are toxic to humans 

Poison  

Synthetic (man-made) substance that is toxic to humans 

Toxic 

Can cause death or illness 

How toxins enter the food chain 

• The stoma 

• Solute by diffusion 

• Solvent by osmosis 

• Toxic gasses entering leaves of plants

• Toxic solutes entering the roots of plants

Remedition – liming  

• Neutralizes the rain after it has fallen  

• pH << 7 

• Base higher than 7  

• Base and acid 

• Base goes back to neutrality  

Prevention  

Removes nitrogen oxides from factories and cars before they are in the air

Catalytic converter

• Do not need to be replaced

• Removes nitrogen oxides from the factories and cars before they get into the air 

Scrubbers  

• A device installed in large factories that uses a sorbent that absorbs the harmful oxides

• Harmful oxides cannot mix with the rain to make acid rain

• They are in the chimneys of factories, so they extract the SO_2. Wet and dry